There has been proposed a conventional technique for photographing a hand of a user, determining the movements of the hand or fingers, and performing processing corresponding to the movements of the hand or the fingers. For example, see Japanese Laid-open Patent Publication No. 2003-346162. In this conventional technique, to determine the movements of the hand or the fingers of the user, an area of the fingers of the hand in an image is determined by using the condition that the hand and the fingers have skin color.
However, the above-mentioned conventional technique has a drawback in that it fails to extract the area of the fingers of the hand.
In the above-mentioned conventional technique, the area of the fingers of the hand is determined by using the condition that the hand has the skin color. However, when a background having a similar color to the color of the fingers overlaps with the fingers of the hand, it is impossible to determine the area of the fingers of the hand by their color. For example, in a state that a finger of the hand of the user overlaps with the face of the user, it is impossible to determine the area of the finger.